Theoretical and Simulative Study on Hydraulic Bridge of Water Hydraulic Servo Valve

2011 ◽  
Vol 181-182 ◽  
pp. 305-309 ◽  
Author(s):  
Xin Hua Wang ◽  
Jia Qing Chang ◽  
Shu Wen Sun ◽  
Gang Zheng
Keyword(s):  
Fluid Dynamics ◽  
Steady State ◽  
Dynamics Simulation ◽  
Computational Fluid Dynamics Simulation ◽  
Servo Valve ◽  
Pressure Distributions ◽  
Hydraulic Servo ◽  
Water Hydraulic ◽  
The Relationship ◽  
Annular Clearance

An analysis has been conducted on the hydraulic bridge of the water hydraulic servo valve with annular clearance between sleeve and spool land as its first hydraulic resistance. Through some formula deductions, the simplified hydraulic bridge is drawn and the relationship between flapper displacement and differential pressure of spool ends, which is demonstrated by the subsequent simulation works, is extracted. By the CFD(computational fluid dynamics) simulation, firstly, the pressure distributions of the flapper face and the fore end face of the nozzle are obtained. Results show that the flapper has an annular area where the existing pressure is negative. Secondly, the relationship between flapper displacement and flow force acting on flapper is also acquired, which is much beneficial to the steady-state and dynamic analysis of the water hydraulic servo valve.

Reduction of steady flow torques in a single-stage rotary servo valve

2018 ◽  
Vol 233 (4) ◽  
pp. 718-727
Author(s):  
He Wang ◽  
Long Quan ◽  
Jiahai Huang ◽  
Guofang Gong ◽  
Xu Yang
Keyword(s):  
Fluid Dynamics ◽  
Steady Flow ◽  
Geometry Optimization ◽  
Single Stage ◽  
Production Costs ◽  
Dynamics Simulation ◽  
External Diameter ◽  
Computational Fluid Dynamics Simulation ◽  
Servo Valve ◽  
Maximum Value

In this paper, geometry optimization of spool is proposed to reduce the steady flow torques in a single-stage rotary servo valve. The steady flow torques under different spool structures are studied by computational fluid dynamics simulation and experimental test and the most effective spool structure is found out. Then, the effects of geometry parameters on the steady flow torques are studied and an optimized solution for reduction of the steady flow torques is suggested by considering the optimization qualities and production costs. The results show that modification of the geometry of spool can make the jet angle at the orifices much closer to 90°, with almost no effect on the flow rate. Processing annular groove in the spool land with increased number of grooves on one side of the spool land is an effective way to reduce the steady flow torques. The maximum value of steady flow torques reduces with a gradual decrease in reduction as the external diameter of annular groove and the number of grooves increase. With the optimized spool structure, the maximum value of steady flow torques can be reduced significantly.

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